Abstract
The structure of coral reef communities results from interacting
evolutionary, ecological and environmental forces. How these factors
interact in structuring these communities at a global scale, and how
such effects might vary among biogeographical regions is unclear. We
partitioned sources of reef community assemblage patterns by
environmental, latent (i.e. unobserved), and random factors on 291 coral
reefs distributed across five biogeographical regions. We then estimated
how these factors were related to variations in abundance and
co-occurrence among 16 functional groups. Latent factors better
explained the distributions of opportunistic functional groups like
algae, whereas environmental factors better explained abundance and
co-occurrence of hard corals. Co-occurrence patterns revealed complex
interactions between coral and algae groups that were not related to
environmental factors but influenced by regional biogeography. Our
results show that environmental factors are not the sole drivers of
coral reef structure highlighting the importance of assemblage-level
interactions and unobserved variables.